Core drill



Jan. 11, 1927.

CORE DRILL Filed April 23. 1923 w. 1-1 JONES ET AL 2 Sheets-Sheet 1 @f www M ran/gas Jan. 11,1927. w. H. JONES ET AL CORE DRILL Filed April 25. 1923 2 Sheets-Shet 2 a body.

Patented Jan. 11, 1927. I

UNITED STATES PATENT OFFICE.

WILLIAM H. JONES AND MARCUS 0F FELLOWS, CALIFORNIA.

CORE DRILL.

Application filed April 23, 1923. Serial No. 633,848.

This invention relates to deep well drilling apparatus, and more particularly to core drills.

It is an object'of the present invention to provide a core drill that is designed to effectively cut a core which can be pulled from the well hole in substantially intact form. Another object is to provide a core drill including an exterior, substantially cylindrical shell within which is secured an inner sleeve formng with the shell an interior passageway for the circulation of liquid or mud in the usual manner of drilling with circulation, and within the sleeve is provided an inner core barrel designed to remain stationary on and surround a core as .it is cut from the earth formation at the bottom of the drilled hole, 7

Another object is to provide means for firmly gripping the core-in the inner core barrel so as to facilitate the extraction of the core with the tool. Another object of the invention is to provide a drilling string having an inner core barrel with means for preventing the downward How of circulating mud or well liquid into the core barrel sleeve, and yet to provide for the escape of liquid from the core barrel as the core enters. Another object is to provide a drilling string with means for preventing the upward passage of well fluid into the drill pipe and thus obviate the possibility of dbris or cavings from finding lodgement in the water holes provided in the tool bit A further object is to provide a core cut ting bit including an annular, toothed cutting shoe which will protect the core from the force of fluid passing through the water holes in the bit body and which will cut ahead of the bit and will steady it while the drill is rotating, therefore serving to act as a guide.

Other objects and advantages will be made manifest in the following specification of an embodiment of the invention illustrated in the accompanying drawings, wherein Figure 1 is a side elevation of the improved tool, a portion of the shell of which is broken away, and a portion of the inner slee e of which is broken away.

Fig. 2 is a longitudinal, central section of a portion of the lower end of the bit as indicated by the bracket line 2 of Figure 1.

Fig. 3 is a central, longitudinal section of the upper portion of the tool and its attach- Figure 3.

The tool of the present invention includes I a suitable length of preferably tubular shell 2, to the lower end of which is attached a coupling 3, and to the upper end of which 18 connected a reducer 4, the smaller end of which is shown as attached to the contignous end of a section 5 of a string of drill pipe forming the stem of the tool. From this it will be seen that a given size shell 2 can be attached to drill stems 5, of any suitable diameter. I

The lower end of the coupling 3 of the shell 2 is provided with a detachable block or body 6, preferably of tool steel or other hard metal, and the lower end of which is provided with a set of substantiall radial cutters 7 forming a bit to cut a ho e of suitable maximum diameter. The bit body 6 is threaded internally at its upper end at 8 to receive the contiguous threaded lower end of What will be here termed as the inner sleeve 10, which willhave a sufiiciently less diameter than the internal diameter of the shell 2 to provide a space 9, through which a circulating medium such as mud or water can be forced'down through the water passages 6 in the body 6.

One of the important objects of the present invention is to provide for the effective cutting and grappling of a core of the earth formation as encountered b the bit at the foot of the well hole, and or that purpose there is provided an annular shoe 12, fitted upwardly within the inner edges of file radial bit blades or cutters 7, and threaded at 13 into the respectively internally threaded, lower portion of the bit body 6. The cutting shoe 12 is provided with teeth 12 on its lower, leading end, and these will serve to cut in advance of the cutting action of the bit blades 7.

As the formation is cut away by the bit and the cutting shoe 12, a core is created which extends upwardly through the hollow, cylindrical shoe and passes into a gripping means here shown as including an annular, longitudinally split slip 14, having a toothed, bored surface 15. .The minor diameter of the slip 14 being slightly less than the minor diameter of the annular cutting shoe 12, it will therefore be seen that as the core enters the split slip 14., the latter will be slightly expanded by the core and its teeth 15- will bind upon the core. The slip la is adapted to be positively contracted to bite upon the core updn the upward movement of the -tool, this being accomplished by providing a conical seat 12 in the bore of the shoe 12 upon which the slip will rest. The slip is loosely mounted in the shoe l2 and will therefore remain stationary on the core while the bit body 6 and the inner sleeve 10 are being rotated during cutting. action.

As the core is cut, the tool bodily descends and the core is enveloped by a core receiving barrel 16, loosely mounted for rotation within the sleeve 10; the core barrel being shown as provided with a circumferential head or band 17 confined against undue axial movement between the inner end of the shoe 12 and a shoulderprovided in the bore of the bit, as clearly shown in Figure 2.

To eliminate undue friction between the rotating parts and the core receiving barrel 16, which is designed to remain stationary about the entering core, th re is provided on the upper end of the core barrel 16, an end thrust and antifriction device reacting against upper end parts carried by the inner sleeve 10. As here shown, on the upper end of the core barrel 16 is mounted a hollow head 18, having a convexly rounded crown 19, which is seated against a con- .cave seat 20 on the lower end of a thrust stem 21, the upper end of which is provided with an end thrust, antifriction bearing 22, engaging a collar 23, which is mounted in the bore of a cap or block 24, threaded at 25 onto the upper end of the barrel sleeve 10. From this it will be seen that downward pressure of the parts on the core barrel 16 is absorbed by the antifriction thrust device interposed between the head of the barrel 16, and the head of its enclosing sleeve 10.

The barrel head 18 is shown as threaded at 18 onto the core barrel l6, and it is also provided witha valve seat 26 to receive .a downwardly closing valve 27, which will open upwardly to permit water trapped in .the core barrel to escape through ports 28,

provided above the valve in the head 18. This valve has the further function of preventing the downward flow of circulating mud or liquid into the core barrel.

Further means are provided at the head of the inner sleeve 10 to prevent downward flow of circulating mud or liquid into the sleeve and yet provide for escape of liquid expelled from the core barrel as the core enters. Such escape means includes a downwardly closing valve 30, mounted on the estates top of a cap 24,-and which cap is provided with escape apertures 31, through which the expelled liquidmay escape past the yielding valve 30. The cap 24 is provided with longitudinally extending passageways as, leading from the interior of the sleeve 10 to the space below the valve 39.

It is desirable to provide for efi ective lubrication of the antifriction bearings 22 arranged within the cap, and further to prevent the access of water to the bearings, and to that end the lower end of the cap is provided with a packing gland 33 and its retainer 3a, which may be fastened by screws 35. The packing gland serves to compress packing 36 between the cap and the thrust stem 21, and therefore will exclude water from the chamber in which the antifriction bearings 22 are mounted. In order to sup-v ply the bearing chamber with lubricant, the cap has a radial aperture 37, through which lubricant may be injected and then the aperture is closed by a plug 38, Figure 5.

To prevent the ascent of well liquid and the sleeve 10, and thence through the cir-' culation passageways 6 in the bit body 6. The passageways discharge from the end 'face of the bit body, and the annular cutting shoe 12 serves to protect the core from the force of the fluid being forced through the holes of the bit.

From the above it will be seen that the drill pipe is therefore empty when itis placed in the well and it is necessary to pump fluid into the well pipe before circulation can be established.

By actual demonstration, a tool of the present invention has been found to produce a foot of core for every foot that the drill is driven, up to the capacity of the length of the core barrel.

The upper end of the cutting shoe 12 provides a shoulder on which to support the core barrel 17. This provides for the supporting 'of the weight of the core barrel independently of the slip so that, in taking a core of soft formation, the slip will be raised and expanded as the core passes up into the barrel. The core does not have to lift the weight of the core barrel in thus passing up into the barrel.

Further embodiment-s, modifications and variations may be resorted .to within the same, a sleeve secured within said shell and in spaced relation thereto, radial cutters secured to said sleeve and said shell, annular cutters secured within said radial cutters, a split slip mounted within said an nular cutters, a' core barrel rotatively mounted within said sleeve, a check valve permitting fiow from the interior of said barrel to the interior of said sleeve, and a second check valve permitting flow from the interior of said sleeve to the interior of said shell.

3. A core drill comprising a rotary drilling shell, cutters carried thereby, a sleeve secured within the shell in spaced relation thereto so as to form circulation passages thereabout, a core barrel rotatably mounted within said sleeve, a check valve permitting flow from the core barrel to the interior of the sleeve, and a second check valve permitting flow from the interior of the sleeve to the interior of the shell.

4. A core drill comprising a rotary drilling shell, cutters carried thereby, a sleeve secured within the shell in spaced relation thereto so as to form circulation passages thereabout, a core barrel rotatably mounted within said sleeve, a check valve permitting flow from'the core barrel to the interior of the sleeve, a second check valve permitting flow from the interior of the sleeveto the interior of the shell, and a third check valve permitting downward flow through the shell mounted adjacent the top thereof.

5. A core drill comprisinga rotary drilling shell, a drill pipe for driving the same, cutters carried by the shell, a sleeve disposed within the shell in spaced relation thereto so as to form circulation passages thereabout, a removable core barrel which is 4 adapted to remain stationary with said core loosely disposed within said sleeve, and a check valve permitting flow from the interior of the core barrel to the interior of the sleeve.

6. A core drill comprising a rotary drilling shell, a drill pipe for driving the same,

cutters carried by the shell, a sleeve disposed within the shell in spaced relation thereto so as to form circulation passages thereabout, a core barrel removably disposed within said sleeve, means providing an outlet leading from adjacent the top of the barrel to the interior of the sleeve, and'a check valve permitting flow from the interior of the sleeve to the interior of the shell.

7. A core drill comprising a rotary drilling shell, a drill pipe for driving the same, cutters carried by the shell, a sleeve disposed within the shell in spaced relation thereto so as to form circulation passages thereabout, a core barrel removably disposed within said sleeve, means providing an outlet leading'from adjacent the top of the barrel to the interior of the sleeve, a check valve permitting flow from the interior of the sleeve to the interior of the shell, and a second check valve permitting downward flow from the drill pipe to the interiorl of the shell.

8. A core drill comprising an outer rotary drilling shell and a drill pipe for driving the same, a sleeve mounted within the shell in spaced relation thereto forming circulation passages, radial cutters mounted in the bottom of the shell and the sleeve, there being passages between the cutters communicating with the space between the sleeve and the shell, a thrust spindle mounted within the sleeve upon an anti-friction bearing, a core barrel rotatably mounted within said sleeve bearing against said thrust spindle, the core barrel having an annular shoulder formed upon its lower end, a shoe threaded within the radial cutters and engageable upon said shoulder for maintaining the barrel within the sleeve, a slip disposed within said shoe, and means forming an outlet adjacent the top of the barrel.

9. A core drill comprising an outer rotary drilling shelland a drillpipe for driving the same, a sleeve mounted within the shell in spaced relation thereto forming circulation passages, radial cutters mounted in the bottom of the shell and the sleeve, there being passages between the cutters communicating with the space between the sleeve and the shell, a thrust spindle mounted within the sleeve upon an anti-friction bearing, a core barrel rotatably mounted within said sleeve bearing against said thrust spindle, the core barrel having an annular shoulder formed upon its lower end, a shoe threaded within the radial cutters and engageable upon said-shoulder for maintaining the bar rel within the sleeve, a slip disposed within said shoe, a check valve-mounted adjacent the top of the barrel permittingupward flow therethrough, a check valve mounted on the sleeve permitting upward flow therethrough,

WILLIAM H. JONES. M. KINNEBREW. 

